How can you tell if your favourite character is, in fact, a manipulative bastard?

A while ago, I decided I was going to read all of Christie’s works. I knew I already read the vast majority of them done - or so I thought.

I can only speak for myself, but I know that I've never bought a book I hadn't intended to read.

I recently finished reading The Monogram Murders by Sophie Hannah. If you don't know, this is Sophie Hannah taking on the continuation...